Program to find Sum of the series 1 * 3 + 3 * 5 + ... . | C # program to find sum of first n terms ; Sn = n * ( 4 * n * n + 6 * n - 1 ) / 3 ; Driver code ; number of terms to be included in the sum ; find the Sn
using System ; class GFG { static int calculateSum ( int n ) { return ( n * ( 4 * n * n + 6 * n - 1 ) / 3 ) ; } static public void Main ( ) { int n = 4 ; Console . WriteLine ( " Sum ▁ = ▁ " + calculateSum ( n ) ) ; } }